Vitreoretinal interface disorders
OCT diagnostic indicators
Prof.Karim A Raafat-Cairo University
The vitreo-retinal interface has 2 components, the posterior cortical vitreous (collagen type II) and the internal limiting membrane (collagen type IV). Several pathological entities may take place at the Vitreomacular interface including: idiopathic macular hole, lamellar macular hole, Epimacular membrane, Vitreomacular traction syndrome and myopic traction maculopathy (myopic foveoschisis, myopic macular hole without retinal detachment and myopic macular hole retinal detachment). Vitreoretinal interface changes may be encountered in association with diabetic retinopathy (diffuse diabetic macular edema and proliferative diabetic retinopathy). Recently, vitreoretinal interface changes have been incriminated in the pathogenesis of exudative age-related macular degeneration. In addition, certain vitreoretinal disorders may be encountered, that cannot be classified to any of the above, and may represent more than one disorder occurring together. Some of these disorders may be inter-related or represent different stages of the same disorder. Tremendous advances in definition; diagnosis and understanding these disorders have been made after the introduction and evolution of Optical Coherence Tomography (OCT). The pathogenesis of these disorders is still not fully understood and several hypotheses have been speculated: Partial posterior vitreous detachment with persistent vitreo-macular adhesion and traction, splitting of the posterior cortical vitreous (vitreoschisis) with persistent adhesion and traction induced by the outer layer and the internal limiting membrane may act as a scaffold for the proliferation of contractile cells. The rationale of surgical treatment is based on complete relieve of traction on the macular area. In most disorders, this can be achieved by identification, peeling and excision of the posterior cortical vitreous, epimacular membranes and internal limiting membrane. Different stains have been proposed to facilitate visualization and complete peeling of these rather transparent membranes.
Source:Piece of ophthalmology
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